What should you do when behind a bicyclist?

Answer: C — Follow the bicycle at a safe distance

It is important to always follow a safe distance when driving behind a bicyclist. This allows enough space for the cyclist to maneuver and make turns safely. Option A is incorrect because increasing your speed could startle the cyclist and increase the risk of an accident. Option B is incorrect because following closely behind the cyclist can be intimidating and make them feel pressured. Option D is incorrect because honking your horn can startle the cyclist and potentially cause them to lose control.